Hey guys, just recently I crashed my Phantom 3 standard and now I am only getting 300 ft range out of the Drone. What do you think is wrong?

There is a possibility that the receiver on the aircraft may have been damaged after the crash. The most that you could do on your own without voiding warranty would be to ensure that all the components (IMU, RC, etc) have been calibrated and relink the RC and WiFi Module to ensure everything is communicating properly. If the issue persists, I would recommend contacting the North American Repair Center for them to take a look at it.

Ok, thanks for your time.